/**
 * Finds an available port starting from a given port.
 * @param {number} startPort - The port to start checking from.
 * @param {number} maxAttempts - The maximum number of attempts to find an available port.
 * @param {number} attempt - The current attempt number.
 * @param {(failedPort: number, tryingPort: number) => void} onWarning - The callback function for warnings.
 * @returns {Promise<string>}
 */
export declare function getAvailablePort(startPort: number, maxAttempts: number, attempt: number, onWarning: (failedPort: number, tryingPort: number) => void): Promise<string>;